Oliyee a



NITED STATES PATENT OFFICE.

OLIVER A. GOOLD, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE UNITED STATES INDELIBLE INK COMPANY, OF SAME PLACE.

WRITING-INK.

SPECIFICATION forming part of Letters Patent No. 263,508, dated August 29, 1882.

Application filed April 18, 1881. (No specimens.)

To all whom it may concern Be it known that I, OLIVER A. GooLn, a citizen of the United States, residing at Boston,in the county of Sufiolk and State of Massaehusetts,have invented certain new and useful Improvements in Writing-Ink; and I do hereby declare the following to be a full,clear,

-and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This compound or combination of ingredients is for the purpose of making an indelible ink, so called,which, when applied to paper material of any sort or kind,is of such a quality as to penetrate its texture and adhere to the minute particles forming the interior portion of the paper, so as to render the removal of the writing or figures absolutely impossible without taking out those particles which have absorbed the writing-fluid, thereby destroying the texture of the draft, check, or note over which said fluid has passed.

The component parts consist of extract of hemlock-bark, which constitutes essentially the indelible portion of my ink. This is diluted or thinned with alcohol to the proper consistency, and as so mixed thereby constitutes the penetrating quality of my ink-that is, mixed with water itwould stand on the surface of the paper, more like ordinary ink, but, as I mentioned above, thinned with alcohol serves to run it into or through the pores or fibers of the paper.

To the above solution I add prussiate of potassium and nitrate of iron. The two latter, in combination with the hemlock extract and spirits, produce a handsome black ink.

pint ofextract of hemlock-bark, one gill ofalcohol, one ounce ofnitrate ofiron, and one-quarter ounce of prussiate of potassium. After this compound has been thoroughly mixed it is ready for use.

This ink I have found invaluable for the purpose of writing checks, drafts, notes, &c., in which there may be any temptation to alter figures or names, as its penetrating quality prevents the alteration in any form whatsoever. It can also be used to great advantage in cancelin g postage-stamps, and when used for Writing does not corrode the pen.

I do not claim separately either of the ingredients herein named, as such are not new.

I am aware that it is not broadly newto produce indelible ink by mixing Prussian blue or the material thereof with a tannic ink, and therefore I do not claim the same; but

What I do claim is- A composition consisting of the following ingredients: extract of hemlock-bark, alcohol, prussiate of potassium, and nitrate of iron, for the purpose set forth.

In testimony whereof I affix my signature in presence of two witnesses.

OLIVER AMES GOOLD.

Witnesses:

THos. O. DUNN, W. H. HARRINGTON. 

